In case you are unfamiliar, this is a doorknob, and this is a door lever. If you are not in the building trade, chances are the difference between the two probably seems cosmetic. But the concept behind Vancouver's ban is simple, and makes perfect sense: Door levers are easier to open for older people, people with injuries, or people with disabilities.

"The door handle most inaccessible could be the round door knob (which requires tight grasping and twisting to operate)," the Center for Independence of Individuals with Disabilities (CID) says on its website, and suggests that doorknobs be replaced with levers.

Vancouver's ban on doorknobs is based around the city's adoption of the concept of universal design, Jeff Lee wrote in The Vancouver Sun this weekend. “The old model was adaptation, or adapted design," Tim Stainton, a professor and director of the School of Social Work at the University of B.C., told Lee. "You took a space and you adapted for use of the person with a disability. What universal design says is let’s turn it around and let’s just build everything so it is as usable by the largest segments of the population as possible.”

Vancouver's ban won't mean the immediate end of doorknobs — it isn't retroactive, for one thing, so buildings currently featuring doorknobs will keep them, and there's no law on changing knobs to levers in your own home — but Lee notes that Vancouver tends to influence Canada's building codes.

You should also consider how many examples of universal design have subtly crept into your everyday life; curb cuts, sidewalk ramps, low-floor buses, even things like closed-captioning for television. In fact, the city's proposals go far beyond simple doorknobs, with things like wider doorways, lower light switches, and higher power outlets. Making things accessible for everyone makes sense to almost everyone. The doorknob may be doomed.